Customer feedback that all the 4 Fan modules reported alarms in BMC at the same time.
1) Plug out and plug in the all 4 Fan modules, the problem is still exist.
2) Check the BMC version which is 1.91, and upgrade it to 2.01. The problem is still exist.
3) Confirm with customer if they installed some high power consumption device, customer feedback some memory and two 82599 NIC cards were installed. Customer is not sure when the system start to report the alarms.
4) Check the part information, there are only two 82599 NIC PCIE device. There is no other high power consumption device.
5) Check the Fan module which is 8056 and the BOM code is 02310YKN
6) Check the CPU which is two E5-2690 V3 CPU
7) Check the produce record, there is only one E5-2620 V3 CPU when produce the server in supply chain department.
8) So we can see that the Fan alarms root cause is CPU changed from CPU E5-2620 V3（TDP：85W） to CPU E5-2690 V3（TDP：135W）
CPU is changed from low power consumption to high power consumption module, but the Fan module didn't changed to corresponding type, lead to the Fan alarms in BMC.
The high power consumption CPU has to work with corresponding Fan module, change the Fan module from 8056(BOM:02310YKN) to 8056+(BOM:02310YKP).
Below types of CPU's power consumption are more than 135W, they can't work with 8056(BOM:02310YKN) . They have to work with 8056+(BOM:02310YKP).